PEOFESSOE MATTEUCCI’S ELECTEO-PHYSIOLOGICAL EESEAECIIES. 
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with the muscle, or with the two rolls of wet paper, which have their nerves stretclunl 
from the lower towards the upper extremity of the thigh. I have repeated this experi- 
ment on the muscles of living pigeons and rabbits, and although the difficulties are much 
greater in these cases, the results were generally the same. 
In order to obtain a still clearer insight into the signification of this experiment, 1 
have operated under the same conditions on the organ of a torpedo, in which the direc- 
tion of the discharge is always clearly indicated by the galvanometer. I suspend a living 
torpedo by the tail, and rapidly lay bare the brain, and with a pair of scissors cut one of 
the electric organs in half, parallel to the length of the fish. Having thus obtained a 
section of the organ, I lay on it (as before on the thigh of a frog) several nerves of galva- 
noscopic frogs, and also the two extremities of a galvanometer. I then stimulate slightly 
the electrical lobe of the brain, and at the same instant the needle of the galvanometer 
deflects, and those frogs only contract whose nerve is extended from the back towards 
the belly of the torpedo, whether that nerve be in contact with the prisms of the organ, 
or complete the circuit of the two already mentioned strips of wet paper in contact with 
the extremities of those prisms. 
From the whole of the experiments referred to, it appears to me that the truth of the 
conclusion which we have deduced is placed beyond all doubt ; namely, that “ A con- 
ducting homogeneous arc laid longitudinally over the surface of a muscle, or applied to 
that muscle at its extremities only, is, at the moment of contraction, traversed by an 
electric discharge directed from the inferior to the superior extremity of the muscle, 
considered in its natural position.” 
Here the experiments finish, and with them the rigorous results which can be deduced 
from them. The difficulties encountered in experimentizing on superior animals have 
deprived these conclusions of the character of generality. Admitting the experiment of 
M. Du Bois Eeymoxd made on the arms of a man, one of which he contracts voluntarily, 
the direction of the current obtained at the instant of contraction would be contrary to 
that of the frog. In the obscurity, not to say entire ignorance, in which we are of the 
structui’e of the electromotive element of muscle, we are unfortunately obliged to satisfy 
ourselves with analogous and equally obscime cases ; as for instance that of the direction 
of the electrical discharge of fishes, mthout a known relation with the structure of the 
organ or the form of the fish. Because an exterior arc applied over an entire muscle in 
repose is traversed by a current in a direction opposite to that which occurs at the 
moment of contraction, ought we to conclude that the two phenomena have a totally 
different origin 1 Or ought we rather to say that, should the form of the electromotor 
element become known to us, we may probably come to explain the opposite direction 
of the current as being due to variations of form produced by contraction! Were we 
not unwilling to diverge into hypothesis or undemonstrated analogies, we might gather 
many arguments tending to show the greater probability of the latter of these two ideas : 
according to the analogous case of the organ of the torpedo, we might also suppose that 
the electrical current is directed in the same sense in muscles in repose as it is in those 
in action. Since there does not exist, as we know, any analogy between the form of the 
